Firstly remove the glass. It's just clipped in place so push the top of the glass so that it tilts all the way up, then insert a large screwdriver under the bottom edge in the centre to prise it out. The adjuster mechanism is held in with three screws. There will be some resistance when you pull it out, this is the plug in the back of it. Pull a bit harder and it will come out. The frame is held in with four screws. The three screws that hold the frame to the mounting bracket are locktited in. I had to drill out the first few after chewing the heads. Heat is the answer. I held a soldering iron against the screwhead for a few minutes (being extremely careful not to damage the surrounding plastic) and the screws came out easy. Two screws hold the plastic casing to the mounting bracket and another one holds the cable in place.